ReadyMix Specification.pdf

REQUIRED SPECIFICATIONS

Performance Standards The Contractor selected must be capable of supplying Ready-Mix Concrete per the following specifications and All Ready-Mix Concrete shall be in conformance with:

1. The latest requirements of the Massachusetts Department of Transportation (MassDOT) Highway Division, Qualified Construction Materials List (QCML) Approved Cement Concrete Producer Mix Designs.

2. The latest DCAMM Standard Specification sections for Cast-In-Place Concrete modified for DOC as follows:

General Provisions Attention is directed to all Sections within this document which are hereby made a part of this Section of the Performance Standards. Please keep in mind no bagged concrete and must be transported in cement truck and poured in place

Description of Work Provide labor, materials and equipment necessary to complete the work of this Section, including but not limited to the following:

Cast-in-place concrete, including concrete materials, mixture design and placement procedures for the following applications:

1. Footings.

2. Foundation walls.

3. Slabs-on-grade.

4. Suspended slabs.

5. Concrete toppings.

6. Building frame members.

7. Building walls.

8. Concrete fill for steel stair and landing pans.

9. Alternates: Not Applicable.

Definitions Cementitious Materials:

Portland cement alone or in combination with one or more of the following: blended hydraulic cement, fly ash and other pozzolans, ground granulated blast-furnace slag, and silica fume; subject to compliance with requirements.

Submittals Product Data:

For each type of product indicated.

Design Mixtures:

For each concrete mixture. Submit alternate design mixtures when characteristics of materials, Project conditions, weather, test results, or other circumstances warrant adjustments.

1. Indicate amounts of mixing water to be withheld for later addition at Project site.

2. Indicate amount of fly ash in the mix.

Material Test Reports:

For the following, from a qualified testing agency, indicating compliance with requirements:

1. Aggregates.

Material Certificates:

For each of the following, signed by manufacturers:

1. Cementitious materials.

2. Admixtures.

3. Curing compounds.

4. Floor and slab treatments.

5. Bonding agents.

6. Adhesives.

Field quality:

Control test and inspection reports.

Quality Assurance Manufacturing Qualifications:

A firm experienced in manufacturing ready-mixed concrete products and that complies with ASTM C 94/C 94M requirements for production facilities and equipment.

Testing Agency Qualifications:

An independent agency, acceptable to authorities having jurisdiction, qualified according to ASTM C 1077 and ASTM E 329 for testing indicated, as documented according to ASTM E 548.

1. Personnel conducting field tests shall be qualified as ACI Concrete Field-Testing Technician, Grade 1, according to ACI CP-01 or an equivalent certification program.

2. Personnel performing laboratory tests shall be ACI-certified Concrete Strength Testing Technician and Concrete Laboratory Testing Technician - Grade I. Testing Agency laboratory supervisor shall be an ACI-certified Concrete Laboratory Testing Technician - Grade II.

Source Limitations:

Obtain each type or class of cementitious material of the same brand from the same manufacturer's plant, obtain aggregate from one source, and obtain admixtures through one source from a single manufacturer.

ACI Publications:

Comply with the following unless modified by requirements in the Contract Documents:

1. ACI 301, "Specification for Structural Concrete."

2. ACI 117, "Specifications for Tolerances for Concrete Construction and Materials."

Concrete Testing Service:

Engage a qualified independent testing agency to perform material evaluation tests and to design concrete mixtures.

Delivery, Storage and Handling Ready-Mix Concrete Materials shall be delivered as early as the next day of receiving a Purchase Order. The following is a list of DOC Facilities to be used for cross referencing the Facility / Location covered:

1. MASAC at Plymouth 1 Bumps Pond Road Plymouth MA 02360

2. Bridgewater State Hospital 20 Administration Road Bridgewater MA 02324

3. Massachusetts Treatment Center 30 Administration Road Bridgewater MA 02324

4. Old Colony Correctional Center 1 Administration Road Bridgewater MA 02324

5. MCI – Norfolk 2 Clark Street, P.O. Box 43 Norfolk MA 02056

6. Pondville Correctional Center 1 Industries Drive, P.O. Box 146 Norfolk MA 02056

7. Milford Headquarters 50 Maple Street Milford MA 01757

8. MCI – Framingham 99 Loring Drive, P.O. Box 9007 Framingham MA 01701

9. NCCI- Concord 976 Barretts Mill Road., P.O. Box 1069 West Concord MA 01742

10. Boston Pre-Release Center 430 Canterbury Street Roslindale MA 02131

11. Lemuel Shattuck Hospital 180 Morton Street Jamaica Plain MA 02130

12. MCI – Shirley 1 Harvard Road., P.O. Box 1218 Shirley MA 01464

13. Souza-Baranowski 1 Harvard Road., P.O. Box 8000 Shirley MA 01464

14. NCCI – Gardner 500 Colony Road., P.O. Box 466 Gardner MA 01440

Products Concrete Materials Cement:

Shall be American-made Portland Cement, free from water soluble salts or alkalis which will cause efflorescence on exposed surfaces. Portland Cement shall be Type II, ASTM C150. Use only one brand of cement for each type of cement throughout the project. The contractor shall be responsible for whatever steps are necessary to ensure that no visual variations in color will result in exposed concrete and shall place on order and secure in advance a sufficient quantity of this (these) cement(s) to complete concrete work specified herein.

• Fly Ash: ASTM C 618

• Ground Granulated Blast-Furnace Slag: ASTM C 989, Grade 100 or 120.

Normal weight Fine Aggregate:

Shall be washed, inert, natural sand conforming to ASTM C33 and following additional requirements:

Sieve Retained Percent #4 0 - 5 #16 25 40 #50 70 87 #100 93 - 97

Fineness Modulus 2.80 ( ± 0.20) Organic Plate 2 max.

Silt 2% max.

Mortar Strength 100% min. compression ratio Soundness 5% max. loss, magnesium sulfate, five cycles

Normal weight Coarse Aggregate:

Shall be well graded crushed stone or washed gravel conforming to ASTM C33 and the following additional requirements:

Designated Size (inches) 3 2 1-1/2 1 3/4 1/2 3/8

F.M. ( ± 0.20) 7.95 7.45 7.20 6.95 6.70 6.10 4.50

Organic Plate 1 Max

Silt 1% Max

Soundness 5% Max Loss Magnesium Sulfate Five Cycles

Maximum designated sizes for normal weight coarse aggregate to be used in concrete sections shall be as noted below, except that sizes shall also be chosen in conjunction with required clearances.

• One and one-half (1-1/2) inches for sections over ten (10) inches in thickness.

• One (1) inch for sections more than eight and up to ten (10) inches in thickness.

• Three-quarter (3/4) inch for sections more than three and up to eight (8) inches in thickness.

Concrete Fill for Steel Stair and Landing Pans:

It will be composed of 1:2:2 mix with three-eighths (3/8) inch maximum size normal weight aggregate and shall be placed with zero (0) inches to one (1) inch slump.

Water:

Shall be from an approved source, potable, clean and free from oils, acids, alkali, organic matter and other deleterious materials.

Admixtures:

Water-reducing agent:

"WRDA" - W.R. Grace & Co.

"PDA25" - Protex Industries, Inc.

"Pozzolith 344H" - Master Builder's Co.

Note: Water-reducing agent shall be by same manufacturer as air-entraining agent.

Air-entraining agent:

"DAREX AEA" - W.R. Grace & Co.

"PROTEX AEA" - Protex Industries "MB-VR" or "MB-AE" - Master Builder's Co.

Superplasticizer:

High-range water-reducer conforming to ASTM C494, Type F or Type G. Admixtures retarding setting of cement in concrete shall not be used without written approval of Designer. Admixtures causing accelerated setting of cement in concrete shall not be used without written approval of Designer.

Concrete Mixtures The Contractor shall recommend, on the basis of trial mixes and strength curves specified below, design mixes for each type and strength of concrete. The Testing Agency will verify that the proposed mixed designs conform to all specification requirements.

Sufficient materials for concrete mix design shall be furnished by Contractor with the proposals, but not less than one week before use. Duplicate small samples plainly and neatly labeled with source, where proposed to be used, date, and name of collector shall be provided and presented to Testing Agency for permanent reference.

Mixes shall be designed in accordance with "Method 1" of ACI 301, and the requirements of this Section. All concrete is normal weight unless specifically designated otherwise; air-dry weight not to exceed 150 lbs. per cubic foot.

Limiting values shown below apply for specific strengths of concrete with coarse aggregates less than one and one-half inches unless noted otherwise in TABLE A below.

TABLE A

Min. Allowable Compressive Strength at 28 days (psi)

Max. Allowable Net Water Content Gallons/Sack*

Minimum Permissible Cement Factor Sacks/Cubic Yard **

4,000 5.75 6.00

3,000 6.50 5.00

* Maximum; decrease if possible. This represents total water in mix at time of mixing, including free water on aggregate.

** Minimum; increase as necessary to meet other requirements.

In all slabs and walls exposed to weather, all concrete shall contain the approved air-entraining admixture as per manufacturer's written instructions, to provide entrained air, by volume, in the cured concrete within 4.5 to 6.5 percent.

Water-Reducing Admixture The approved water-reducing admixture shall be used in all concrete, in accordance with manufacturer's written instructions.

Concrete slabs, including slabs on grade, shall have a maximum water cement ratio of 0.45. The approved superplasticizer shall be used in all concrete slabs, including slabs on grade.

Water content and cement content of concrete to be used in work shall be based on curve showing relation between water content, cement content, and seven (7) and twenty-eight (28) day compressive strengths of concrete made using proposed materials. Curves shall be determined by four (4) or more points, each representing an average of at least three (3) test specimens at each age and shall have range of values sufficient to yield desired data, including all compressive strengths required by Contract Documents, without extrapolation. Designing a mix of concrete to be used in work, as determined from curve, shall correspond to following test strengths (TABLE B) obtained in laboratory trial mixtures, but in no case shall result in mixed conflict with limiting values as specified in TABLE A.

TABLE B

Minimum Strength of Lab Trial Mixes (psi)

Design Strength Trial Mix Strength 7-days Trial Mix Strength 28-days

4,000 3,800 5,000

3,000 2,700 3,750

Any deviation from the approved mix design, which Contractor deems desirable under certain project conditions, will not be allowed without written approval of Designer. Cost of any additional testing by Testing Agency associated therewith shall be paid for by Contractor.

Miscellaneous Materials Grout Shall be ready-to-use metallic aggregate product requiring only addition of water at job site such as "Embeco Pre-mixed Grout" by Master Builder's; "Vibro-Foil Ready-Mixed" by W.R. Grace & Co.; or "Ferrolith G" by Sonneborn Building Products, Inc. Grout shall be easily workable and shall have no drying shrinkage at any age. Compressive strength of grout (two (2) inch x two (2) inch cubes) shall not be less than 5,000 psi at seven (7) days, and 7,500 psi at twenty-eight (28) days.

Execution Inspection Examine all work prepared by others to receive work for this Section and report any defects affecting installation to the DOC Representative for correction. Commencement of work will be construed as complete acceptance of preparatory work by others.

• Inspection shall be performed by a structural engineer licensed in the Commonwealth of Massachusetts. Certify compliance with shop drawings.

Handling Storage and Protection of Materials Handle and store materials separately in such manner as to prevent intrusion of foreign matter, segregation, or deterioration.

Do not use foreign materials or those containing ice. Remove improper and rejected materials immediately from point of use.

Cover materials during construction period. Stockpile concrete constituents properly to assure uniformity throughout project.

Mixing Consistency and Delivery of Concrete Concrete shall be ready-mixed, produced by plant acceptable to DOC. Hand or site mixing shall not be done. Constituents, including admixtures except certain corrosion inhibitors and superplasticizers, shall be batched at central batch plant.

Admixtures shall be premixed in solution form and dispensed as recommended by manufacturer.

Central plant and rolling stock equipment and methods shall conform with Truck Mixer and Agitator Standard of Truck Mixer Manufacturer's Bureau of National Ready-Mixed Concrete Association, and Contract Documents. Consistency of concrete at time of deposit shall be as follows:

Portion of Structure Slump Recommended Max Range

Walls, Columns Four (4) inch Three (3) inch – five (5) inch

Slabs, Beams Three (3) inch Two (2) inch – Four (4) inch

Ready mixed concrete shall be transported to site in watertight agitator or mixer trucks loaded and not in excess of rated capacities. Discharge at site shall be within one and one-half (1-1/2) hours after cement was first introduced into mix. Discard cement not discharged within one and one-half (1-1/2) hours and dispose of legally. Concrete with a temperature greater than eighty-five (85) degrees F. shall not be placed. Central mixed concrete shall be plant mixed a minimum of five (5) minutes.

Agitation shall begin immediately after premixed concrete is placed in the truck and shall continue without interruption until discharged. Transit mixed concrete shall be mixed at mixing speed for at least ten (10) minutes immediately after charging truck followed by agitation without interruption until discharged. Concrete shall be furnished by a single plant unless accepted by the Designer in writing.

Retempering of concrete which has partially hardened, that is, mixing with or without additional cement, aggregates, or water, will not be permitted.

Placing Concrete The intent of this Specification is that concrete shall not be pumped. Remove water and foreign matter from forms and excavations and, except in freezing weather or as otherwise directed, thoroughly wet wood forms just prior to placing concrete. Place no concrete on frozen soil and provide adequate protection against frost action during freezing weather.

To secure full bond at construction joints, surfaces of concrete already placed, including vertical and inclined surfaces, shall be thoroughly cleaned of foreign materials and laitance, roughened with suitable tools such as chipping hammers or wire brushes, and recleaned by stream of water or compressed air. Well before new concrete is deposited, joints shall be saturated with water. After free or glistening water disappears joints shall be given thorough coating of neat cement slurry mixed to consistency of very heavy paste. Surface shall receive coating of approximately one-eighth (1/8) inch thick; this shall be scrubbed in by means of stiff bristle brushes. New concrete shall be deposited before neat cement dries or changes color.

Do not place concrete having slump outside of allowable slump range. Transport concrete from mixer to place of final deposit as rapidly as practical by methods which prevent separation of ingredients and displacement of reinforcement, and which avoid rehandling. Deposit no partially hardened concrete. When concrete is conveyed by chutes, equipment shall be of such size and U-shaped design as to ensure continuous flow in chute. Flat (coal) chutes shall not be employed. Chutes shall be of metal or metal lines and different portions shall have approximately the same slope. Slope shall not be less than twenty-five

(25) degrees nor more than forty-five (45) degrees from horizontal and shall be such as to prevent segregation of ingredients.

Discharge end of chute shall be provided with baffle plate or spout to prevent segregation. If discharge end of chute is more than five (5) feet above surface of concrete in forms, spout shall be used, and lower and maintained as near surface of deposit as practicable. When the operation is intermittent, the chute shall be discharged into hopper. Chute shall be thoroughly cleaned before and after each run and debris and any water used shall be discharged outside forms. Concrete shall not be allowed to flow horizontally over distances exceeding five feet.

Concrete shall be placed in such manner as to prevent segregation, and accumulations of hardened concrete on forms or reinforcement above mass of concrete being placed. To achieve this end, suitable hoppers, spouts with restricted outlets and tremies shall be used as required.

During and immediately after depositing, concrete shall be thoroughly compacted by means of internal type mechanical vibrators or other tools, or by spading to produce required quality of finish. Vibration shall be done by experienced operators under close supervision and shall be carried on only enough to produce homogeneity and optimum consolidation without permitting segregation of constituents or "pumping" of air. Vibrators used for normal weight concrete shall operate at speed at not less than 7,000 vpm and be of suitable capacity. Do not use vibrators to move concrete. Vibration shall be supplemented by proper wooden spade puddling to remove included bubbles and honeycomb adjacent to visible surfaces. At least one vibrator shall be on hand for every ten (10) cubic yards of concrete placed per hour, plus one (1) spare. Vibrators shall be operable and on site prior to starting placement.

Vertical lifts shall not exceed eighteen (18) inches. Vibrate completely through successive lifts to avoid pour lines. Vibrate first lift thoroughly until top of lift glistens to avoid stone pockets, honeycomb, and segregation.

Concrete shall be deposited continuously, and in layers of such thickness that no concrete will be deposited on concrete which has hardened sufficiently to cause formation of seams and planes of weakness within section. If section cannot be placed continuously between planned construction joints, as specified, field joint and additional reinforcement shall be introduced so as to preserve structural continuity. Designers shall be notified in any such case.

Cold joints, particularly in exposed concrete, including "honeycomb", are unacceptable. If they occur in concrete surfaces exposed to view, Designer will require that entire section in which blemish occurs be removed and replaced with new materials at Contractor's expense.

When placing exposed concrete walls or columns, strike corners of forms rapidly and repeatedly from outside along full height while depositing concrete and vibrating.

Chutes, hoppers, spouts, adjacent work, etc. shall be thoroughly cleaned before and after each run and water and debris shall be discharged outside form.

Curing and Protection When concrete is placed at or below ambient air temperatures of forty (40) degrees F. or whenever in opinion of Designer, such or lower temperatures are likely to occur within forty-eight (48) hours after placement of concrete, cold weather concreting procedures, according to ACI 306 and as specified herein, shall be followed. To this end, the entire area affected shall be protected by adequate housing or covering, and heating. No salt, chemicals or other foreign materials shall be used in the mix to lower the freezing point of concrete.

Protect concrete work against injury from heat, cold, and defacement of any nature during construction operations. Concrete shall be treated and protected immediately after concreting or cement finishing is completed, to provide continuous moist curing above fifty (50) degrees F. for at least seven (7) days, regardless of ambient air temperatures.

Curing compounds will not be permitted for slab and beams.

Keep a permanent temperature record showing date and outside temperature for concreting operations. Thermometer readings shall be taken at start of work in the morning, at noon, and again late in the afternoon. Locations of concrete placed during such periods shall likewise be recorded, in such manner as to show any effect temperatures may have had on construction. Copies of temperature record shall be distributed daily to Designer.

Repairing and finishing of formed and Architectural Concrete Surfaces In accordance with the provisions of ACI 301, Chapter 10, all concrete shall have "smooth form finish".

The intention of this Specification is to require forms, mixtures of concrete, and workmanship so that concrete surfaces will require no patching, except for plugging of tie holes. However, where patching is acceptable to Designer, procedure described below shall be followed.

Defective concrete and honeycombed areas shall not be patched unless examined and approval is given by Designer. If such approval is received by Contractor, areas involved shall be chipped down square and at least one inch deep to sound concrete by means of cold chisels or pneumatic chipping hammers. If honeycomb exists around reinforcement, chip to provide clear space at least three-quarter inch wide all around steel to afford proper ultimate bond thereto. For areas less than one and one-half inches deep, patch shall be made in same manner as described above for filling unformed concrete surfaces, care being exercised to use crumbly-dry (non-trowelable) mixtures and to avoid sagging. Thicker repairs shall require build-up in successive days; each layer being applied as described. To aid strength and bonding of multiple layer repairs, non-shrink, non-metallic aggregate shall be used as an additive as follows:

Materials Volumes Weight

Cement 1.00 1.00

Non-Metallic Aggregate 0.15 0.25

Sand 1.50 1.55

For very heavy (generally, formed) patches, pea gravel may be added to mixture and proportions modified as follows:

Materials Volumes Weight

Cement 1.00 1.00

Non-Metallic Aggregate 0.20 0.33

Sand 1.00 1.00

Pea Gravel 1.50 1.55

After hardening, rub lightly as described above to form tie holes.

• Mortar for patching shall be same mix as above except aggregate shall pass a No. 14 sieve.

• For all concrete to receive "smooth" finish, remove formwork fins and clean the entire surface of grease, form oil, laitance, dust, and other foreign matters.

• "Smooth" finish shall consist of having all fins removed, joint marks smoothed off, blemishes removed, and surfaces left smooth and unmarried.

• Begin finishing operations as soon as practicable after removal of forms, continue with curing operations after finishing is completed. After concrete has been well cured, carefully inspect the surfaces. Remove any fins, rough spots, streaks, hardened mortar or grout and other foreign material. Patch defects with finishing mortar as specified above, to satisfaction of Designer.

Field Quality Control Independent Testing Agency:

Cooperate with the Independent Testing Agency engaged by DOC for field quality control activities for the Work of this Section.

Additional inspections and retesting of materials which fail to comply with specified material and installation requirements shall be performed at Contractor's expense.